kernel.git/arch/x86/boot/compressed/misc.c, branch linux-3.19.y

x86, boot: Skip relocs when load address unchanged

2015-01-20T11:37:23Z

On 64-bit, relocation is not required unless the load address gets changed. Without this, relocations do unexpected things when the kernel is above 4G. Reported-by: Baoquan He Signed-off-by: Kees Cook Tested-by: Thomas D. Cc: Vivek Goyal Cc: Jan Beulich Cc: Junjie Mao Cc: Andi Kleen Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20150116005146.GA4212@www.outflux.net Signed-off-by: Thomas Gleixner

Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-12-10T20:10:24Z

Pull x86 boot and percpu updates from Ingo Molnar: "This tree contains a bootable images documentation update plus three slightly misplaced x86/asm percpu changes/optimizations" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64: Use RIP-relative addressing for most per-CPU accesses x86-64: Handle PC-relative relocations on per-CPU data x86: Convert a few more per-CPU items to read-mostly ones x86, boot: Document intermediates more clearly

x86-64: Handle PC-relative relocations on per-CPU data

2014-11-04T19:43:14Z

This is in preparation of using RIP-relative addressing in many of the per-CPU accesses. Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/5458A15A0200007800044A9A@mail.emea.novell.com Signed-off-by: Thomas Gleixner

x86, kaslr: Prevent .bss from overlaping initrd

2014-11-01T21:20:50Z

When choosing a random address, the current implementation does not take into account the reversed space for .bss and .brk sections. Thus the relocated kernel may overlap other components in memory. Here is an example of the overlap from a x86_64 kernel in qemu (the ranges of physical addresses are presented): Physical Address 0x0fe00000 --+--------------------+ <-- randomized base / | relocated kernel | vmlinux.bin | (from vmlinux.bin) | 0x1336d000 (an ELF file) +--------------------+-- \ | | \ 0x1376d870 --+--------------------+ | | relocs table | | 0x13c1c2a8 +--------------------+ .bss and .brk | | | 0x13ce6000 +--------------------+ | | | / 0x13f77000 | initrd |-- | | 0x13fef374 +--------------------+ The initrd image will then be overwritten by the memset during early initialization: [ 1.655204] Unpacking initramfs... [ 1.662831] Initramfs unpacking failed: junk in compressed archive This patch prevents the above situation by requiring a larger space when looking for a random kernel base, so that existing logic can effectively avoids the overlap. [kees: switched to perl to avoid hex translation pain in mawk vs gawk] [kees: calculated overlap without relocs table] Fixes: 82fa9637a2 ("x86, kaslr: Select random position from e820 maps") Reported-by: Fengguang Wu Signed-off-by: Junjie Mao Signed-off-by: Kees Cook Cc: Josh Triplett Cc: Matt Fleming Cc: Ard Biesheuvel Cc: Vivek Goyal Cc: Andi Kleen Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414762838-13067-1-git-send-email-eternal.n08@gmail.com Signed-off-by: Thomas Gleixner

asmlinkage, x86: Add explicit __visible to arch/x86/*

2014-05-05T23:07:44Z

As requested by Linus add explicit __visible to the asmlinkage users. This marks all functions visible to assembler. Tree sweep for arch/x86/* Signed-off-by: Andi Kleen Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin

x86, boot: Move memset() definition in compressed/string.c

2014-03-19T22:44:09Z

Currently compressed/misc.c needs to link against memset(). I think one of the reasons of this need is inclusion of various header files which define static inline functions and use memset() inside these. For example, include/linux/bitmap.h I think trying to include "../string.h" and using builtin version of memset does not work because by the time "#define memset" shows up, it is too late. Some other header file has already used memset() and expects to find a definition during link phase. Currently we have a C definitoin of memset() in misc.c. Move it to compressed/string.c so that others can use it if need be. Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1395170800-11059-6-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin

x86, boot: Move optimized memcpy() 32/64 bit versions to compressed/string.c

2014-03-19T22:43:59Z

Move optimized versions of memcpy to compressed/string.c This will allow any other code to use these functions too if need be in future. Again trying to put definition in a common place instead of hiding it in misc.c Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1395170800-11059-4-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin

x86, kaslr: Select random position from e820 maps

2013-10-13T10:12:19Z

Counts available alignment positions across all e820 maps, and chooses one randomly for the new kernel base address, making sure not to collide with unsafe memory areas. Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/1381450698-28710-5-git-send-email-keescook@chromium.org Signed-off-by: H. Peter Anvin

x86, kaslr: Return location from decompress_kernel

2013-10-13T10:12:07Z

This allows decompress_kernel to return a new location for the kernel to be relocated to. Additionally, enforces CONFIG_PHYSICAL_START as the minimum relocation position when building with CONFIG_RELOCATABLE. With CONFIG_RANDOMIZE_BASE set, the choose_kernel_location routine will select a new location to decompress the kernel, though here it is presently a no-op. The kernel command line option "nokaslr" is introduced to bypass these routines. Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/1381450698-28710-3-git-send-email-keescook@chromium.org Signed-off-by: H. Peter Anvin

x86, relocs: Move ELF relocation handling to C

2013-08-08T04:00:04Z

Moves the relocation handling into C, after decompression. This requires that the decompressed size is passed to the decompression routine as well so that relocations can be found. Only kernels that need relocation support will use the code (currently just x86_32), but this is laying the ground work for 64-bit using it in support of KASLR. Based on work by Neill Clift and Michael Davidson. Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/20130708161517.GA4832@www.outflux.net Acked-by: Zhang Yanfei Signed-off-by: H. Peter Anvin